question_answer 6)

Write about the slope stabilization methods by drainage.  

Answer:

There are three methods for doing this   (i) Protect Vulnerable Areas Keep surface drainage water away from vulnerable areas, such as steep slopes, loose soil and non-vegetated surfaces.   (ii) Collect Runoff Collect and direct water from verandahs, driveways, and non-vegetated surfaces into catch basins; confine water flow in drainpipes such as a drainage ditch, dry well, gutter, natural drainage or holding pond. Roof water may go directly to the drainpipe.   (iii) Intercept Surface Water When surface water flows onto your property, and where a discharge point is available, dig a shallow, gently sloping ditch to intercept the water and direct it into a natural water course, vegetated drainage area, road pavement or road drainage ditch. Your intercepting ditch should be nearly horizontal, with a minimum slope, sufficient to allow water to flow slowly. Smoothen the sides of the ditch and grow vegetation; keep all ditches free of debris.